Implementing a current source for a particular circuit may present challenges. The implementation of a current source can often include large, complex, and costly components such as power transistors, power inductors, and controller integrated circuits (ICs). In addition, high frequency switching is often involved, which has the potential to create unwanted electromagnetic interference (EMI) side effects which must be mitigated through additional shielding or filtering. Therefore, implementing a minimum number of current sources in a given design is beneficial as it may help minimize overall cost and complexity of the system. Thus, when multiple loads in a system are required to be driven with constant currents, a designer might employ a current mirror in order to share one current source between two or more loads.
One application of this concept is in new exterior light emitting diode (LED) lighting products that are using increasing numbers of discrete LEDs to create unique styling features that distinguish each vehicle as being unique. However, as the number of LEDs increase, figuring out an effective and cost effective method to drive them and have a uniform appearance is becoming a challenge. If all LEDs are placed in a series configuration, the drive voltage required to feed the LEDs exceeds practical limits of IC process capability. If one begins to divide them into parallel strings, it is difficult to ensure that each LED receives the same amount of current. Unequal currents will result in differences in either or both color or intensity, which could cause customer dissatisfaction as well as regulatory compliance concerns.
Accordingly, it is desirable to provide a solution to which could balance currents in multiple loads given a single constant current source. Furthermore, other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.